A new class of pyrazolopyridine nucleus with fluorescent properties, obtained through either a radical or a Pd arylation pathway from N-azinylpyridinium N-aminides.
The synthesis of dipyridopyrazole and pyridopyrazolopyrazine derivatives--both of which incorporate a 3-aryl moiety--can be achieved in moderate yields by intramolecular radical arylation of pyridinium N-aminides using tris(trimethylsilyl)silane and azobisisobutyronitrile. Improved results were obtained on using Pd direct arylation in conjunction with microwave irradiation. A preliminary study into the fluorescent properties of the target compounds is also reported.
Abet
Valentina
V
Departamento de Química Orgánica, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain.
Nuñez
Araceli
A
Mendicuti
Francisco
F
Burgos
Carolina
C
Alvarez-Builla
Julio
J